Pellets In Pharmaceuticals: An Overview of Pelletization Techniques And Excipients For Optimized Drug Delivery

Abstract

In recent years, pellets have emerged as a preferred alternative to traditional tablets and capsules in pharmaceutical formulations due to their numerous advantages. These small, free-flowing spherical particles, commonly referred to as beads, seeds, or nonpareils, offer benefits such as uniform size distribution, enhanced flowability, and improved packing characteristics. Unlike traditional solid dosage forms, pellets enable better drug distribution in the gastrointestinal tract, reducing variability in drug absorption and minimizing irritation to the stomach lining.Pelletization involves various techniques, each with its own merits and applications. Conventional methods like powder layering, extrusion-spheronization (ES), and solution/suspension layering are widely used in industrial settings. ES, in particular, is favored for its reliability and scalability in producing drug-loaded or neutral pellets. Additionally, advanced techniques such as wet spherical agglomeration, crystallo-co-agglomeration, melt pelletization, cryopelletization, and freeze pelletization have expanded the possibilities for pellet formulation, offering solutions for immediate and controlled drug release.Natural polymers and excipients, including sugar, starch, chitosan, pectin, carrageenan, alginates, xanthan gum, and talc, play a crucial role in pellet formulation. These materials contribute to the mechanical stability, sphericity, and release characteristics of the pellets. Semi-synthetic excipients like cellulose derivatives (HPMC, HEC) and synthetic polymers such as crospovidone, carbopol, polyethylene glycol, and polyethylene oxide have also been explored for their potential to enhance pellet properties.This review provides a comprehensive overview of the various pelletization methods, with a focus on the extrusion-spheronization technique, and discusses the potential excipients used in pellet formulation. The discussion highlights the importance of selecting appropriate methods and materials to achieve desired pellet characteristics, ensuring consistent drug delivery and therapeutic outcomes.